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4 What is Gastroparesis? –A symptomatic chronic disorder of the stomach characterized by delayed gastric emptying in the absence of mechanical obstruction –A stomach disorder in which food is digested more slowly than normal. –In a healthy digestive system, strong muscular contractions move food from the stomach through the digestive tract. –With gastroparesis, stomach muscles work poorly (or not at all), thus preventing the stomach from emptying properly.

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6 Prevalence The true prevalence of gastroparesis is not known; however, it has been estimated that up to 5 million persons in the US may suffer from this condition. * In a survey patients with documented chronic gastroparesis patients, it was found that the origins were about 36 percent idiopathic and 29 percent diabetic, with the remaining amount attributed to several other causes. ** * Abell T, et al.. Nutrition in Clinical Practice ** Soykan I, et al.Dig Dis Sci

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9 Idiopathic Gastroparesis Delayed gastric emptying without apparent cause or underlying abnormality may be the most common form of gastroparesis Symptoms fluctuate: patient may have episodes of pronounced symptoms interspersed with relatively symptom- free intervals Patients are frequently young or middle-aged women Kendall, McCallum. Gastroenterology Parkman et al. Gastroenterology 2004.

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10 Symptoms may resolve after months or even years – Patients with a viral trigger tend to have slow resolution of their symptoms over several years – Patients without a viral trigger tend to show less improvement over time Idiopathic Gastroparesis Parkman et al. Gastroenterology 2004.

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13 Likely to result from impaired neural control of gastric motility, possibly at the level of the vagus nerve Problems with blood glucose control may be the first indication that a diabetic patient is developing gastroparesis – Gastroparesis contributes to poor glycemic control because of unpredictable delivery of food into the duodenum – Delayed gastric emptying with continued insulin administration may produce hypoglycemia Diabetic Gastroparesis Parkman. Gastroenterology 2004.

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14 Post-surgical* Gastroparesis Any surgery of the upper intestinal tract (esophagus, stomach or duodenum) may result in injury to the vagus nerve** Gastroparesis may occur as a complication of a variety of surgical procedures*** – Post-vagotomy - Most often peptic ulcer surgery with vagotomy – Post-fundoplication - Complication of fundoplication to treat GERD – Post-bariatric - Most commonly Roux-en-Y gastric bypass for obesity – Post lung and heart-lung transplantation * Use of gastric electrical stimulation for post-surgical gastroparesis is not an approved indication for Enterra ® Therapy. **American College of Gastroenterolgy Website ***Parkman et al. Gastroenterology 2004.

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20 Oral diet modifications should include adjustments in composition, consistency, size, and frequency of meals Patients should be prescribed meals which are low in fat and fiber, in order to –Promote gastric motility –Reduce symptoms of nausea, vomiting and abdominal pain If solid foods are not tolerated, a liquid diet can be tried, supplemented with vitamins and minerals Diet Modification Koch. Practical Gastroenterol Karras, Pfeifer. Curr Ther Endocrinol Ther 1997.

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21 Drug Therapy The commonly used pharmacotherapy for gastroparesis has been a combination of prokinetic agents and antiemetics, such as –Metoclopramide –Erythromycin –Cisapride (no longer on the market) –Domperidone (not currently available in US) Side effects are common with both prokinetics and antiemetics Drug therapy options are limited

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23 Prokinetic agents to increase GI motility –Metoclopramide: side effects may restrict use in up to 30% of patients – Erythromycin: side effects (nausea, vomiting) may mimic those of gastroparesis –Cisapride: only available under compassionate use/limited access programs due to link with cardiac arrhythmias and sudden death Drug Therapy

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26 Total parenteral nutrition (TPN) –Intravenous delivery of nutrition Often utilized as an end-stage option when nutrition is severely compromised and weight loss extensive – Should be temporary due to complication risk The cost of TPN is at least ten times greater than enteral feeding, with some patients consuming over $200,000 annually in healthcare costs Options for Drug-Refractory Patients

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34 Enterra Therapy U.S. Indication “Enterra Therapy is indicated for the treatment of patients with chronic, intractable (drug-refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic origin.” Designated as Humanitarian Use Device (HUD) September 1999 by the FDA. Approved as Humanitarian Device Exemption (HDE) March 2000 by the FDA.

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45 Surgical Procedure Performed under general anesthesia Surgical procedure lasts 1-2 hours –Laparoscopy –Laparotomy Neurostimulator activated in OR or anytime after implant based on the surgeon’s medical judgment X-ray post-surgery to document initial lead position Evaluate neurostimulator parameters before discharge Parkman et al. Gastroenterology 2004.

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46 Using laparotomy or laparoscopy, two intramuscular leads with electrodes are fixed to the muscle of the lower stomach The leads are attached to the neurostimulator –Laparotomy (abdominal incision) –Laparoscopy (abdominal visualization via an endoscope) Surgical Procedure Parkman et al. Gastroenterology 2004.

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49 Documentation Fill out the Device Tracking Registration Form and affix serial number stickers: one IPG and two leads Mail top copy to Medtronic in prepaid, self- addressed envelope –This will ensure the patient receives a permanent ID card for the device and is registered with Medtronic in case any product or safety notice must be sent Place two copies in the patient’s chart Place printed parameters (pre-and post-implant) in the progress notes in the patient’s chart

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64 Complications/Adverse Events System removed in four patients due to: –Infection of neurostimulator pocket (two patients) –Pain related to lead perforation of stomach –Erosion of neurostimulator through skin Surgery to reposition and re-anchor neurostimulator in one patient due to discomfort from system migration Abell et al. Gastroenterology 2003.

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66 Enterra Therapy Reimbursement, Coding and Billing Coverage and payment is available and is dependent on individual insurance carriers. Medtronic Gastroenterology Economic Solutions has resources available to help with specific DRG, CPT, and ICD-9 CM codes.

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69 Enterra  Therapy for Gastroparesis: Product technical manual must be reviewed prior to use for detailed disclosure. Indications: The Medtronic Enterra Therapy System for gastric electrical stimulation (GES) is indicated for use in the treatment of chronic, intractable (drug refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic etiology. Contraindications: The Enterra Therapy System is contraindicated in patients whom the physician determines are not candidates for surgical procedures and/or anesthesia due to physical or mental health conditions. Do not use shortwave diathermy, microwave diathermy or therapeutic ultrasound diathermy (all now referred to as diathermy) on patients implanted with a neurostimulation system. Energy from diathermy can be transferred through the implanted system and can cause tissue damage at the location of the implanted electrodes, resulting in severe injury or death. Diathermy is further prohibited because it can also damage the neurostimulation system components resulting in loss of therapy, requiring additional surgery for system explantation and replacement. Warnings: This system has not been evaluated for pregnancy, pediatric use, or patients under the age of 18, or over the age of 70. Strong sources of electromagnetic interference (EMI) can result in serious injury, system damage, or operational changes to the system. Strong sources of EMI include MRI, electrocautery, radiofrequency (RF)/microwave ablation, external defibrillators, ultrasonic equipment, radiation therapy, and theft detectors. Patients on anticoagulation therapy may be at a greater risk for post-operative complications. The system may be affected by or adversely affect other implantable devices such as cardiac pacemakers and cardioverters/defibrillators. Rupture or piercing of the neurostimulator can result in severe burns. The use of non-Medtronic components with this system may result in damage to Medtronic components, loss of therapy, or patient injury. When possible, identify and treat any infections remote to the implant site prior to surgery. It is recommended that the neurostimulator implant site be irrigated with antibiotic solution during surgery and that IV antibiotics be administered perioperatively. Infections at the implant site almost always require the surgical removal of the implanted system. Avoid excess lead slack in the abdominal cavity. The lead can become entangled with or erode into the bowel, which may result in bowel obstruction, bowel perforation, intra-abdominal infection, bowel resection and may require system revision. Precautions: Clinicians and patients should follow programming guidelines and precautions provided in product manuals. Patients should avoid manipulating or rubbing the neurostimulator system components, which can cause component damage, skin erosion, or stimulation at the implant site. Patients should be detoxified from narcotics prior to implant so that the effects of stimulation can be properly assessed. Patients should avoid activities that may put undue stress on the implanted neurostimulation system components. Patients should not scuba dive below 10 meters of water or enter hyperbaric chambers above 2.0 atmosphere absolute (ATA). Electromagnetic interference, postural changes, and other activities may cause shocking or jolting. Adverse Events: Adverse events related to the system include infection, stomach wall perforation, migration/erosion of the neurostimulator, programming difficulty, undesirable change in stimulation, implant site pain, hemorrhage, hematoma, migration/dislodgement of the lead, extra- abdominal pain, seroma, concomitant muscle stimulation, allergenic or immune system response to implanted materials, loss of therapeutic effect, and gastrointestinal complications including upper and lower gastro-intestinal (GI) symptoms. Humanitarian Device: Authorized by Federal law for use in the treatment of chronic intractable (drug refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic etiology. The effectiveness of this device for this use has not been demonstrated. For further information, please call Medtronic at and/or consult Medtronic’s website at USA Rx Only. Rev 0709